"Immaterial" redirects here. For the song by Haircut 100, see Paint and Paint.

Immaterialism is the theory propounded by Bishop Berkeley in the 18th century which holds that there are no material objects, only minds and ideas in those minds. Berkeley summarized his theory with the motto "esse est percipi" ("To be is to be perceived"), but went on to elaborate it with God as the source of consensus reality and other particulars.

Today this theory is considered the first formulation of subjective idealism, a branch of idealism and a form of phenomenalism. Since it is not falsifiable, it is a theory not of science but of metaphysics and other philosophical methods. The idea that objects exist independently of mind is not testable or provable by the scientific method, because all objects we would wish to examine must enter our awareness in order to experiment on them.

Christiantheology also refers to the incorporeal and immaterial in reference to God, the Holy Spirit, angels, and demons. This is in contrast to the corporeal human body of the physical realm that decays over time. The incorporeal is unchanging, whereas the corporeal is ever changing. Jesus was resurrected in a mysterious way that suggests some kind of incorporeal soul that can exist independently of the physical body. The ghostly appearance of various saints, prophets, and other supernatural beings imply some kind of immaterial realm. Some supernatural miracles can also imply the existence of the immaterial realm.

Bishop Berkeley's assessment of immaterialism was criticized by Samuel Johnson, as recorded by James Boswell. Responding to the theory, Dr. Johnson exclaimed "I refute it thus!" while kicking his shoe into a rock. This episode is cited by Stephen Dedalus in James Joyce's "Ulysses," chapter three. Reflecting on the "ineluctable modality of the visible," Dedalus conjures the image of Johnson's refutation, before engaging in his own refutation - closing his eyes and feeling the rocks under his feet while walking along the beach. However Berkeley did not confine his theory to visual perception, but perception by any of the five senses.